Process for the alkylation of .alpha., .beta.-unsaturated aldehydes

A process for preparing at least one aldehyde represented by the structure:

• ##STR14## comprising the step of intimately admixing a halide having the structure R.sub.1 X wherein X is chloro with an unsaturated aldehyde having the structure:
• ##STR15## in the presence of an alkali metal hydroxide, an inert solvent and a "phase transfer agent", wherein one of the dashed lines is a double bond and the other of the dashed lines is a single bond;
• wherein R.sub.1 is prenyl or benzyl, R.sub.2 is methyl, n-propyl, 4-methyl-3-pentenyl or n-hexyl, and R.sub.3 and R.sub.4 are each the same or different and are hydrogen, methyl or ethyl with the proviso that when R.sub.3 is methyl or ethyl the dashed line between the beta carbon atom and the gamma carbon atom represents a double bond and when R.sub.3 is hydrogen, either of the dashed lines is a double bond;
• said phase transfer agent having the structure:
• ##STR16## wherein at least one of the groups R'.sub.1, R'.sub.2, R'.sub.3 and R'.sub.4 is C.sub.6 -C.sub.14 alkaryl or C.sub.6 -C.sub.20 alkenyl, and the other of R'.sub.1, R'.sub.2, R'.sub.3 and R'.sub.4 is C.sub.1 -C.sub.8 alkyl, and Z represents halogen, the temperature of the reaction being in the range of from about 10.degree. up to about 150.degree. C, the mole ratio of unsaturated aldehyde:halide being from 0.5:1.5 up to about 1.5:0.5, the mole ratio of alkali metal hydroxide:halide being from about 0.75:1 up to about 1.5:1 and the concentration of "phase transfer agent" in grams per mole of unsaturated aldehyde being from 0.5 up to 25.